Saturday, February 15, 2014

Shoulder arthroplasty for rheumatoid arthritis

These authors report on shoulder arthroplasties (108 hemiarthroplasties, 195 total shoulder arthroplasties) for rheumatoid arthritis. 255 arthroplasties were available for clinical analysis and 188 for radiographic analysis.

Survivorship free of revision at 10 years was 92.9% for total shoulder arthroplasty and and 87.9% for hemiarthroplasty. The most common indications were glenoid loosening (5%) and infection (2%) for total shoulder revision and glenoid arthrosis (7%) for hemiarthroplasty revision.

Approximately 30% of humeral components and 73% of glenoid components had periprosthetic lucencies. There was a shift in position of the glenoid in 33% of total shoulders, and 36% were "at risk." Eighty-one percent of hemiarthroplasties had moderate or severe glenoid erosion.

Comment: While the authors found that patients with an intact rotator cuff, pain relief and range of motion are more improved with totals compared with hemis, this may be due to the selection of hemiarthroplasty in the tighter shoulder or the shoulder with a greater degree of glenoid erosion in this retrospective study. Compare an article published a decade ago.

We commented recently that revision rate is subjective - as demonstrated in this study, a third of the patients had failed glenoid components, but only a small percentage of these patients chose to have a revision.

Our practice is to propose total shoulder arthroplasty to patients with rheumatoid shoulder arthritis, but to inform them that severe tightness or severe glenoid erosion may preclude the use of a glenoid component, resulting in a hemiarthroplasty. The cuff is often thin or deficient in these patients and their bone may be fragile, so we exercise 'rheumatoid rules' of extreme gentleness in performing the surgery.